Composite materials have been developed in many fields in order to obtain products that maintain the desirable characteristics of each component, while minimizing the less desirable characteristics. For instance, glass fibers can offer excellent tensile strength characteristics, but have a dielectric constant of about 6, and thus are often unsuitable for electrical applications at high usage rates. However, glass fibers can be combined with resins, such as certain fluorocarbon resins, that exhibit desirable electrical characteristics to form composite materials having good electrical as well as physical properties.
Other fibrous composite materials, for instance those providing high strength, often include highly engineered fibers such as glass fibers, steel fibers, carbon fibers, Kevlar® fibers (poly-paraphenylene terephthalamide), and the like, held in a stable matrix. These materials can offer excellent strength characteristics but can also be very dense, which can be problematic where weight of the product is a factor, e.g., body armor, automobile parts, boat materials, etc.
Moreover, when the composite materials must be designed to meet high engineering specifications, cost can begin to be a problem. For instance, in order to meet engineering specifications with regard to flexibility, modulus, density, electrical characteristics, and the like, though various combinations of different materials might be found that can form a composite material to meet the specifications, formation and materials costs often become prohibitive. As a result, characteristics must often be relinquished in order to provide an affordable product to the consumer.
Polyolefin materials can bring many desirable characteristics to composites. For example, polyolefin materials can be resistant to degradation and erosion, the raw materials can be easy to obtain as well as fairly inexpensive, and they can have low density and dielectric loss characteristics. Unfortunately, the low strength characteristics of polyolefin yarns and fibers have been such that even when combined with a secondary, relatively strong material in a composite, the strength requirements of the desired application have not been met. Moreover, as these polymers are generally nonpolar by nature, they often cannot be utilized with known thermoset resins common to fibrous composites, as a strong bond between the thermoset matrix and the polyolefin fiber cannot be formed.
While there have been improvements in polyolefin fibers and composite materials incorporating fibrous polymeric materials, there remains room for further improvement and variation within the art.